Case Report: Two Cases of Chemotherapy Refractory Metastatic Penile Squamous Cell Carcinoma With Extreme Durable Response to Pembrolizumab

Treatment approaches in advanced penile cancer: targeted therapies and immunotherapy

Penile cancer is a rare genitourinary malignancy which can be treated with surgery or radiation for localized disease, but often requires systemic treatment with chemotherapy for recurrent or metastatic disease. With the emergence of immune checkpoint inhibitors and targeted therapies for specific genomic aberrations in the treatment of over a dozen other cancers, recent studies have sought to identify therapies other than chemotherapy in treating this uncommon cancer. Several ongoing trials involving immune checkpoint inhibitors, tyrosine kinase inhibitors, and antibody drug conjugates are attempting to identify additional therapies.

Immune-based Therapies for Penile Cancer

This article reviews penile squamous cell carcinoma (PSCC), a rare genitourinary cancer that has been increasing in prevalence. It discusses emerging therapies, focusing on immunotherapy, vaccine therapy, and cell-based treatments, especially in the context of human papillomavirus-related PSCC. Factors influencing these therapies are discussed. These include the immune microenvironment, programmed cell death ligand-1 expression, and tumor immune cell infiltration. This article also highlights immune checkpoint inhibitors and related clinical trials. This review supports the use of personalized medicine in treating PSCC. It stresses the need for collaborative studies and data sharing to create specific treatment plans and achieve better outcomes.

Advances in molecular basis of response to immunotherapy for penile cancer: better screening of responders

Penile cancer is a rare malignant tumor of the male urinary system. The treatment benefit of standard first-line chemotherapy is not ideal for patients with locally advanced or metastatic lymph nodes. Immunotherapy has brought new treatment strategies and opportunities for patients with penile cancer. At present, clinical studies on immunotherapy for penile cancer have been reported, and the results show that it is effective but not conclusive. With the development of immunotherapy and the progress of molecular research technology, we can better screen the immunotherapy response population and explore new combination treatment regimens to evaluate the best combination regimen and obtain the optimal treatment options, which is also an important research direction for the immunotherapy of penile cancer in the future.

Penile cancer: ESMO-EURACAN Clinical Practice Guideline for diagnosis, treatment and follow-up

•This ESMO CPG provides recommendations for diagnosis, staging, pathology, treatment and follow-up of penile cancer. •Algorithms for the management of primary penile tumours and inguinal lymph nodes are provided. •The author group encompasses a multidisciplinary group of experts from different institutions and countries in Europe. •Recommendations are based on available scientific data and the authors’ collective expert opinion. •In clinical practice, all recommendations provided need to be discussed with patients in a shared decision-making approach.

Retifanlimab in Advanced Penile Squamous Cell Carcinoma: The Phase 2 ORPHEUS Study

BACKGROUND AND OBJECTIVE

Patients with advanced penile squamous cell carcinoma (PSCC) have poor outcomes and very limited therapeutic options are available. Most PSCC cases have high PD-L1 expression, which is associated with worse prognosis. Immunotherapy targeting PD-L1 could benefit patients with PSCC. Our aim was to evaluate the efficacy and safety of the anti-PD-1 antibody retifanlimab in patients with advanced/metastatic PSCC.

METHODS

ORPHEUS was a single-arm, multicenter, phase 2 trial in 18 patients with advanced/metastatic PSCC, previously untreated with anti-PD-1/anti-PD-L1 agents. Patients received retifanlimab 500 mg intravenously every 4 wk for up to 2 yr. The primary endpoint was the objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors v1.1. Secondary endpoints included the clinical benefit rate (CBR), disease control rate, duration of response (DoR), time to response, progression-free survival (PFS), overall survival (OS), maximum tumor shrinkage, and safety. The Wilson method was used for the primary endpoint, and the Clopper-Pearson and Kaplan-Meier methods for secondary endpoints.

KEY FINDINGS AND LIMITATIONS

Median follow-up was 7.2 mo. The ORR was 16.7% (95% confidence interval [CI] 5.8-39.2); three patients had a partial response. Median DoR was 3.3 mo (range 1.8-8.5). The CBR was 22.2% (95% CI 6.4-47.6%). Median PFS was 2.0 mo (95% CI 1.6-3.3) and median OS was 7.2 mo (95% CI 3.0-9.8). One patient (5.6%) experienced grade 3 treatment-related adverse events (AEs). There were no grade >= 4 treatment-related AEs. The small sample size is the main limitation.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Single-agent retifanlimab exhibited signals of clinical activity in advanced/metastatic PSCC, with no new safety signals. Further investigation of retifanlimab in this setting is warranted.

PATIENT SUMMARY

Advanced penile cancer of the squamous cell type is a rare tumor with poor prognosis. The aggressiveness of this cancer is usually associated with high levels of a protein called PD-L1. We investigated whether retifanlimab, an immunotherapy drug against PD-1, has activity against this type of penile cancer. Tumor regression or stabilization occurred in one-third of the patients and the side effects were manageable.

Insights into the management of penile squamous cell carcinoma: from conventional approaches to emerging novel therapies

INTRODUCTION

Penile squamous cell carcinoma (PSCC), a rare genitourinary cancer, is associated with poor outcomes due to limited treatment effectiveness, especially in advanced stages.

AREAS COVERED

While chemotherapy and/or surgery remain the standard of care, emerging therapies like immunotherapy, targeted therapy, and human papillomavirus (HPV) directed therapies show promise. Key to advancing treatment is understanding the immune microenvironment to gain insights into tumor resistance mechanisms and potential therapeutic targets. The scarcity of data on PSCC is a major obstacle in advancing research for this rare cancer.

EXPERT OPINION

Future research should prioritize collaborative efforts across various research centers and countries. Enhancing data sharing and pooling resources can lead to a more comprehensive understanding of PSCC, ultimately supporting the development of precision medicine strategies tailored to this specific cancer type. This collaborative approach is essential for making significant strides in PSCC treatment and care.

Multiplex Immunofluorescence Captures Progressive Immune Exhaustion with Advancing Penile Squamous Cell Cancer Stage

Penile squamous cell carcinoma (PSCC) is a rare and deadly malignancy. Therapeutic advances have been stifled by a poor understanding of disease biology. Specifically, the immune microenvironment is an underexplored component in PSCC and the activity of immune checkpoint inhibitors observed in a subset of patients suggests immune escape may play an important role in tumorigenesis. Herein, we explored for the first time the immune microenvironment of 57 men with PSCC and how it varies with the presence of human papillomavirus (HPV) infection and across tumor stages using multiplex immunofluorescence of key immune cell markers. We observed an increase in the density of immune effector cells in node-negative tumors and a progressive rise in inhibitory immune players such as type 2 macrophages and upregulation of the PD-L1 checkpoint in men with N1 and N2-3 disease. There were no differences in immune cell densities with HPV status.

Comprehensive genomic profiling of penile squamous cell carcinoma and the impact of human papillomavirus status on immune-checkpoint inhibitor-related biomarkers

BACKGROUND

Advanced penile squamous cell carcinoma (pSCC) is a rare and aggressive malignancy with limited success of immune-checkpoint inhibitors (ICIs). Approximately half of pSCC cases are associated with human papillomavirus (HPV) infection.

METHODS

Evaluation was done retrospectively of the landscape of somatic alterations and ICI-related biomarkers in pSCC by using the Caris Life Sciences data set with the aim to establish signatures for HPV-dependent oncogenesis. The pSCC tumors were analyzed by using next-generation sequencing (NGS) of DNA and RNA. Programmed death ligand 1 (PD-L1) expression was evaluated by immunohistochemistry (IHC). Microsatellite instability (MSI) was tested by fragment analysis, IHC (SP142; ≥1%), and NGS. Tumor mutational burden (TMB)-high was defined as ≥10 mutations/Mb. HPV16/18 status was determined by using whole-exome sequencing (WES) when available. Significance was adjusted for multiple comparisons (q value < .05).

RESULTS

NGS of the overall cohort (N = 108) revealed TP53 (46%), CDKN2A (26%), and PIK3CA (25%) to be the most common mutations. Overall, 51% of tumors were PD-L1+, 10.7% had high TMB, and 1.1% had mismatch repair-deficient (dMMR)/MSI-high status. Twenty-nine patients had their HPV status made available by WES (HPV16/18+, n = 13; HPV16/18-, n = 16). KMT2C mutations (33% vs. 0%) and FGF3 amplifications (30.8% vs. 0%) were specific to HPV16/18+ tumors, whereas CDKN2A mutations (0% vs. 37.5%) were exclusive to HPV16/18- tumors. TMB-high was exclusively found in the HPV16/18+ group (30.8%). The two groups had comparable PD-L1 and dMMR/MSI-H status.

CONCLUSIONS

In a large and comprehensive NGS-based evaluation of somatic alterations in pSCC, HPV16/18+ versus HPV16/18- pSCCs were molecularly distinct tumors. Our finding that TMB-high is exclusive to HPV16/18+ tumors requires confirmation in larger data sets.

PLAIN LANGUAGE SUMMARY

Penile squamous cell carcinoma (pSCC) is a rare and aggressive malignancy in the advanced setting, with poor prognosis and little success with immune-checkpoint inhibitors (ICIs) in an unselected patient approach. Human papillomavirus (HPV) infection is a known risk factor for pSCC; its impact on genomic tumor profiling is less defined. Using next-generation sequencing, we explored the genetic landscape and ICI-related biomarkers of pSCC and HPV-driven oncogenic molecular signatures. Our results indicate that HPV-positive and HPV-negative pSCCs are molecularly distinct tumors. Increased tumor mutational burden is associated with HPV-positive tumors, and could serve as a biomarker for predicting therapeutic response to ICI-based therapies. Our results support the growing literature indicating that HPV status in pSCC can be used to guide patient stratification in ICI-based clinical trials.

Safety and efficacy of immune checkpoint inhibitors in advanced penile cancer: report from the Global Society of Rare Genitourinary Tumors

BACKGROUND

Treatment options for penile squamous cell carcinoma are limited. We sought to investigate clinical outcomes and safety profiles of patients with penile squamous cell carcinoma receiving immune checkpoint inhibitors.

METHODS

This retrospective study included patients with locally advanced or metastatic penile squamous cell carcinoma receiving immune checkpoint inhibitors between 2015 and 2022 across 24 centers in the United States, Europe, and Asia. Overall survival and progression-free survival were estimated using the Kaplan-Meier method. Objective response rates were determined per Response Evaluation Criteria in Solid Tumours 1.1 criteria. Treatment-related adverse events were graded per the Common Terminology Criteria for Adverse Events, version 5.0. Two-sided statistical tests were used for comparisons.

RESULTS

Among 92 patients, 8 (8.7%) were Asian, 6 (6.5%) were Black, and 24 (29%) were Hispanic and/or Latinx. Median (interquartile range) age was 62 (53-70) years. In all, 83 (90%) had metastatic penile squamous cell carcinoma, and 74 (80%) had received at least second-line treatment. Most patients received pembrolizumab monotherapy (n = 26 [28%]), combination nivolumab-ipilimumab with or without multitargeted tyrosine kinase inhibitors (n = 23 [25%]), or nivolumab (n = 16 [17%]) or cemiplimab (n = 15 [16%]) monotherapies. Median overall and progression-free survival were 9.8 months (95% confidence interval = 7.7 to 12.8 months) and 3.2 months (95% confidence interval = 2.5 to 4.2 months), respectively. The objective response rate was 13% (n = 11/85) in the overall cohort and 35% (n = 7/20) in patients with lymph node-only metastases. Visceral metastases, Eastern Cooperative Oncology Group (ECOG) performance status of 1 or higher, and a higher neutrophil/lymphocyte ratio were associated with worse overall survival. Treatment-related adverse events occurred in 27 (29%) patients, and 9.8% (n = 9) of the events were grade 3 or higher.

CONCLUSIONS

Immune checkpoint inhibitors are active in a subset of patients with penile squamous cell carcinoma. Future translational studies are warranted to identify patients more likely to derive clinical benefit from immune checkpoint inhibitors.

Assessment of PD-L1, TROP2, and nectin-4 expression in penile squamous cell carcinoma

OBJECTIVES

There is an unmet need for therapeutically relevant biomarkers for advanced penile squamous cell carcinoma (pSCC). Proposed immunohistochemistry (IHC)-based biomarkers include programmed death-ligand 1 (PD-L1), trophoblast cell-surface antigen 2 (TROP2), and nectin-4; however, there is a paucity of data pertaining to these biomarkers. Herein, we investigated the expression of PD-L1, TROP2, and nectin-4 in a well-annotated cohort of pSCCs.

METHODS

A single-institution pathology archive was queried for patients who had a partial or total penectomy for pSCC between January 2000 and December 2022. Whole-slide sections were stained with antibodies against PD-L1 (22C3), TROP2, and nectin-4. Expression in tumor cells was quantified using H-scores (0-300). Associations between IHC expression, human papilloma virus (HPV) status, clinicopathologic findings, and outcome parameters were evaluated.

RESULTS

This study included 121 patients. For PD-L1, the median combined positive and H-scores were 1 and 0, respectively; 32.7 % of the cases had an H-score>0. Compared to PD-L1-negative tumors, PD-L1-positive tumors had higher pT stage and grade. The median TROP2 and nectin-4 H-scores were 230 and 140, respectively, with high TROP2 and nectin-4, defined by an H-score>200, noted in 80.7 % and 10.9 % of cases, respectively. High-risk HPV-positive cases had higher TROP2 and nectin-4 scores compared to HPV-negative cases. Patients with high TROP2 expression had significantly more disease progression, and patients with high nectin-4 expression had significantly fewer deaths due to disease.

CONCLUSIONS

High expression of TROP2 and nectin-4 in pSCC support evaluation of these markers as therapeutic targets pending validation of our findings.

Cemiplimab as First Line Therapy in Advanced Penile Squamous Cell Carcinoma: A Real-World Experience

In the treatment of cancer, immune checkpoint inhibitors (ICIs) have demonstrated significantly greater effectiveness compared to conventional cytotoxic or platinum-based chemotherapies. To assess the efficacy of ICI's in penile squamous cell carcinoma (pSCC) we performed a retrospective observational study. We reviewed electronic medical records of patients with penile squamous cell carcinoma (SCC), diagnosed between January 2020 and February 2023. Nine patients were screened, of whom three were ineligible for chemotherapy and received immunotherapy, cemiplimab, in a first-line setting. Each of the three immunotherapy-treated patients achieved almost a complete response (CR) after only a few cycles of therapy. The first patient had cerebral arteritis during treatment and received a high-dose steroid treatment with resolution of the symptoms of arteritis. After tapering down the steroids dose, the patient continued cemiplimab without further toxicity. The other two patients did not have any toxic side effects of the treatment. To the best of our knowledge, this is the first real world report of near CR with cemiplimab as a first-line treatment in penile SCC.

Metastatic Penile Squamous Cell Carcinoma Responsive to Enfortumab Vedotin

Penile squamous cell carcinoma is a rare disease with very limited data to guide treatment decisions. In particular, there is minimal evidence for effective therapies in the metastatic setting. Here, we present a case of metastatic penile squamous cell carcinoma with response to the Nectin-4 inhibitor enfortumab-vedotin-ejfv (EV). EV was selected due to the evidence of the high expression of Nectin-4 in squamous cell carcinomas, including penile carcinoma. The patient had both radiographic and symptomatic improvement after two cycles of treatment, despite having been treated with multiple prior lines of traditional chemotherapy. This case provides support for the use of antibody-drug conjugates (ADC), including EV, in this disease with few other options in the advanced setting. Further studies examining Nectin-4 and ADCs in penile squamous cell carcinoma should be completed, as high-quality evidence is needed to guide treatment after initial progression for these patients.

Atezolizumab With or Without Radiotherapy for Advanced Squamous Cell Carcinoma of the Penis (The PERICLES Study): A Phase II Trial

PURPOSE

Patients with advanced penile squamous cell carcinoma have a poor prognosis (21% 2-year overall survival [OS] from diagnosis). We assessed the activity of atezolizumab (anti-PD-L1) in patients with advanced penile cancer, with or without radiotherapy (RT).

PATIENTS AND METHODS

A single-center, nonrandomized phase II study with two treatment arms was conducted in 32 patients with histologically confirmed advanced penile cancer. All patients received atezolizumab (1,200 mg) once every 3 weeks. Twenty patients, who were expected to benefit from RT for locoregional disease control, received additional irradiation. The primary end point was 1-year progression-free survival (PFS) for the complete cohort and was reached if the actual 1-year PFS was at least 35%. Secondary end points included OS, objective response rate (ORR), and tolerability. Exploratory biomarker analyses were conducted in pretreatment specimens.

RESULTS

Median follow-up was 29.1 months (IQR, 18.1-33.5). Grade 3-4 adverse events related to atezolizumab or RT were observed in 3/32 (9.4%) and 13/20 (65%) patients, respectively. One-year PFS was 12.5% (95% CI, 5.0 to 31.3), which did not meet the study's primary end point. Median OS was 11.3 months (95% CI, 5.5 to 18.7). In the objective response-evaluable population (n = 30; 93.8%), the ORR was 16.7% (95% CI, 6 to 35), including 2 (6.7%) complete responders and 3 (10%) partial responders. Improved PFS was observed in patients with high-risk human papillomavirus (hrHPV)-positive tumors (P = .003) and those with high infiltration of intratumoral CD3+CD8+ T cells (P = .037).

CONCLUSION

Although the primary end point of 1-year PFS was not met, durable antitumor activity to atezolizumab was observed in a subset of patients. Biomarkers, such as hrHPV and intratumoral CD3+CD8+ T-cell infiltration, may help to better select responders.

[Systemic treatment of penile cancer: New concepts? New achievements?]

Systemic chemotherapy has been in use for metastatic penile carcinoma for years, but its success is limited. Its significance is largely associated with its role in multimodal treatment for lymphatic metastasis in the context of radical lymph node surgery. In cases of limited lymph node involvement, the combination of surgical treatment plus cisplatin- and taxane-based triple combinations may be curative. Advances in the understanding of molecular changes in penile cancer and the search for potential therapy targets have led to numerous studies. Although there is evidence of efficacy of immunotherapeutics, no significant therapeutic improvements have been seen in the clinical routine.

Therapeutic Approaches to Penile Cancer: Standards of Care and Recent Developments

Penile cancer is a rare malignancy, most commonly diagnosed in older men, associated with poor outcomes, dramatic decline in quality of life and sexual function. Squamous cell carcinoma is the most common histopathology of penile cancer, accounting for 95% of all cases. Localized, early-stage penile cancer can be effectively managed through penile-sparing techniques in many cases, though advanced stages of penile cancer carry a poor prognosis. Current innovative treatments are exploring the role of targeted therapy, HPV-directed therapy, immune checkpoint inhibitors and adoptive T-cell therapies in treatment and prevention of relapse of penile cancer. Clinical trials are investigating the potential of targeted therapies and immune checkpoint inhibitors in advanced penile cancer. This review examines the current management of penile cancer and highlights future directions in research and treatment.

Dyspnea Secondary to Mediastinal Mass: A Rare Presentation of Metastatic Penile Squamous Cell Carcinoma

Penile squamous cell carcinoma is a rare diagnosis in the United States; however, the incidence is significantly higher in developing countries. This cancer is categorized into human papilloma virus (HPV)-associated and independent disease. In this article, we present a rare case of HPV-independent penile squamous cell carcinoma. Our patient was a 75-year-old Caucasian male who initially presented with a penile ulcer which was managed with partial penectomy and adjuvant chemotherapy. The patient was monitored on surveillance and did not pursue lymph node dissection. He was noted to have recurrence with metastatic disease 5 years after his initial presentation. Due to the aggressive nature of his disease, the patient was admitted to the hospital and treated with chemotherapy and immunotherapy.

Combination of Durvalumab and Chemotherapy to Potentially Convert Unresectable Stage IV Penile Squamous Cell Carcinoma to Resectable Disease: A Case Report

Penile squamous cell carcinoma is a rare disease entity with poor overall survival in an advanced stage. Few studies have investigated the role of immunotherapy in advanced penile squamous cell carcinoma. Herein, we report a case of stage IV unresectable penile squamous cell carcinoma presenting with anal bleeding and urethra obstruction who responded dramatically to combination therapy of durvalumab and cisplatin-based chemotherapy. The patient had HPV-positive penile squamous cell carcinoma, cT3N3M0, with concomitant anus squamous cell carcinoma. After 2 months of the combination treatment, almost all bulky inguinal lymph nodes shrank, and the main tumor of the anus and penis responded completely. A durable response was seen 16 months after initiating the combination therapy. This case report highlights the potential role of the combination of immunotherapy and chemotherapy in patients with advanced penile cancer. The promising results of this combination resulted in the conversion of unresectable disease to a potentially curable disease.

PD-L1 is associated with the prognosis of penile cancer: A systematic review and meta-analysis

BACKGROUND

Previous studies have explored the role of PD-L1 in the survival outcomes of penile cancer patients with controversies existed. Thus, the meta-analysis was conducted to report and review the association between PD-L1 and survival in penile cancer patients.

METHODS

PubMed, Cochrane Library, EMBASE, and Web of Science were all searched, screened, and reviewed by June 1, 2022. Hazard ratio (HR) was used to evaluate the relationship between PD-L1 and survival outcome, and odds ratio (OR) was for tumor features.

RESULTS

Nine retrospective studies (1,003 patients) were incorporated. The prevalence of PD-L1 in patients with penile cancer was 51.4% (95% CI = 42.1%-60.8%, I 2 = 88.5%). Higher PD-L1 on tumor cells was related to shorter cancer-specific survival (CSS) in patients (HR = 1.578, 95% CI = 1.227-2.029, I 2 = 23.3%), but had no associations with overall survival (OS) (HR = 1.123, 95% CI = 0.511-2.465, I 2 = 0.0%). Subgroup analysis indicated that higher PD-L1 was related to shorter CSS in Caucasus (HR = 1.827, 95% CI = 1.355-2.465, I 2 = 0.0%) only. Furthermore, PD-L1 had associations with tumor stage (pT1 vs. pT2-4, OR = 0.480, 95% CI = 0.346-0.667, P = 0.001) and tumor grade (Well and moderate vs. Poor, OR = 0.377, 95% CI = 0.264-0.538, P < 0.001). PD-L1 positivity was also related to lymph node (LN) status (pN0/NX vs. pN1-3, OR = 0.541, 95% CI = 0.385-0.759, P = 0.001) and HPV status (Positive vs. Negative, OR = 0.510, 95% CI = 0.322-0.810, P = 0.003). A trend toward statistical significance between PD-L1 and histological types was also observed (Usual SCC vs. Others, OR = 1.754, 95% CI = 0.984-3.124, P = 0.070).

CONCLUSIONS

PD-L1 over-expression was related to worse survival outcomes and several clinicopathological features of penile cancer. PD-L1 expression can be applied to select appropriate treatment strategies for penile malignancies.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=343041, identifier CRD42022343041.

Immune landscape and immunotherapy for penile cancer

Penile cancer is a rare malignancy and usually refers to penile squamous cell carcinoma (PSCC), which accounts for more than 95% of all penile malignancies. Although organ-sparing surgery is an effective treatment for early-stage PSCC, surgical intervention alone is often not curative for advanced PSCC with metastases to the inguinal and/or pelvic lymph nodes; thus, systemic therapy is required (usually platinum-based chemotherapy and surgery combined). However, chemotherapy for PSCC has proven to be of limited efficacy and is often accompanied by high toxicity, and patients with advanced PSCC usually have poor prognosis. The limited treatment options and poor prognosis indicate the unmet need for advanced PSCC. Immune-based therapies have been approved for a variety of genitourinary and squamous cell carcinomas but are rarely reported in PSCC. To date, several studies have reported high expression of PDL1 in PSCC, supporting the potential application of immune checkpoint inhibitors in PSCC. In addition, human papillomavirus (HPV) infection is highly prevalent in PSCC and plays a key role in the carcinogenesis of HPV-positive PSCC, suggesting that therapeutic HPV vaccine may also be a potential treatment modality. Moreover, adoptive T cell therapy (ATC) has also shown efficacy in treating advanced penile cancer in some early clinical trials. The development of new therapeutics relies on understanding the underlying biological mechanisms and processes of tumor initiation, progression and metastasis. Therefore, based on the interest, we reviewed the tumor immune microenvironment and the emerging immunotherapy for penile cancer.

Combination of Pembrolizumab and Stereotactic Body Radiation Therapy in Recurrent Metastatic Penile Squamous Cell Carcinoma: A Case Study

The prognosis for patients with penile squamous cell carcinoma metastatic to regional lymph nodes or distant sites remains poor with limited treatment options, especially after the failure of first-line chemotherapy. Clinical trials evaluating the use of checkpoint inhibitor therapy, or the use of checkpoint inhibitor therapy with stereotactic body radiation therapy for the treatment of metastatic penile squamous cell carcinoma, are currently unavailable. In this case report, we present a patient with relapsed advanced penile squamous cell carcinoma and an unknown (human papilloma virus) HPV status and borderline programmed death-ligand 1 (PD-L)1 status who was treated with pembrolizumab and stereotactic body radiation therapy. This patient achieved a complete durable treatment response despite having genomic features of an immunologically "cold" tumor. This case highlights the importance of investigating more into the treatment of these tumors that lack genomic features that classically have been observed to be susceptible to treatment with immunotherapy or immunotherapy augmented with stereotactic body radiation therapy in solid tumors, particularly in metastatic penile squamous cell carcinoma.

Sintilimab-Induced Diabetic Ketoacidosis in a Patient with Radiation and Multichemorefractory Penile Cancer: A Case Report and Literature Review

Penile squamous cell carcinoma (PSCC) is a rare disease. The treatment options for advanced penile cancer are often limited, and the prognosis remains poor. We reported a 52-year-old male recurrent and metastatic PSCC patient with high PD-L1 expression (90%) and TMB (14.4 muts/Mb). He had undergone penectomy, bilateral inguinal lymph node dissection, and excision of the abdominal wall mass. Despite cisplatin-based concurrent chemoradiotherapy and sequential chemotherapy with docetaxel plus cisplatin then being carried out, the carcinoma still progressed. The patient then obtained progression-free survival with continuous sintilimab, although he experienced the new onset of ICI-induced diabetes after 24 cycles of sintilimab and required sustained insulin treatment. He had negative type 1 diabetes-associated autoantibodies and the susceptible HLA genotype DR3-DQ2 haplotype. This is the first patient with radiation and multichemorefractory PSCC who has obtained the remarkable anti-tumor effect of partial regression exceeding 32 months during continuous sintilimab and anlotinib treatment.

An update on treatment of penile cancer

Penile cancer is a rare malignancy, particularly in industrialized nations. In the United States, rates are approximately less than 1 per 100,000 men per year with just over 2000 new cases per year. However, there is significantly increased prevalence in developing nations, with limited treatment expertise and reduced access to care, further driving an unmet clinical need. The most noteworthy risk factor for penile cancer is the association with human papillomavirus infection, which may be present in up to 50% of all penile carcinomas. In addition to local primary tumor approaches, multimodality treatment strategies are vital to patients with clinical regional nodal disease, locally advanced disease. Presence and degree of lymph node involvement remains the most important prognostic factor and patients may benefit from multiple treatment strategies. Interim analysis data from the first randomized clinical trial is expected to yield results in mid/late 2024–early 2025. These treatment approaches include neoadjuvant chemotherapy, adjuvant therapy, including chemotherapy and radiation. Systemic therapy for distant recurrent or metastatic disease is primarily a platinum-based chemotherapy, however with poor overall response. As poor outcomes remain high, particularly in indigent populations, there remains an unmet need for these patients, particularly for high level randomized trials and novel therapeutics. In this review, we will highlight treatment updates for penile cancer. In addition to standard of care, we will review novel lines of therapies including immunotherapies and targeted therapies as well as sequencing approaches.

Emerging Therapies in Penile Cancer

Advances in the treatment of rare tumors like penile cancer were always hampered by the lack of deep comprehension of the molecular biology and genomic and epigenomic alterations involved in carcinogenesis and tumor progression, as well as by the difficulty in recruitment of patients for prospective clinical trials. Despite the high rates of cure in early localized penile cancers with surgery or other local procedures, locally advanced and metastatic tumors require systemic treatment, with chemotherapy being the current standard, but with high toxicity and no proven real impact on survival. Recent important findings of frequent genomic alterations and mutation signatures in penile cancer have motivated several trials in new modalities of systemic treatments, especially immunotherapy. This review aims to present the most recent advances and the prospect of new modalities of systemic therapies with ongoing studies in penile cancer.

Immunotherapeutic Approaches for the Treatment of HPV-Associated (Pre-)Cancer of the Cervix, Vulva and Penis

Human papillomavirus (HPV) infection drives tumorigenesis in almost all cervical cancers and a fraction of vulvar and penile cancers. Due to increasing incidence and low vaccination rates, many will still have to face HPV-related morbidity and mortality in the upcoming years. Current treatment options (i.e., surgery and/or chemoradiation) for urogenital (pre-)malignancies can have profound psychosocial and psychosexual effects on patients. Moreover, in the setting of advanced disease, responses to current therapies remain poor and nondurable, highlighting the unmet need for novel therapies that prevent recurrent disease and improve clinical outcome. Immunotherapy can be a useful addition to the current therapeutic strategies in various settings of disease, offering relatively fewer adverse effects and potential improvement in survival. This review discusses immune evasion mechanisms accompanying HPV infection and HPV-related tumorigenesis and summarizes current immunotherapeutic approaches for the treatment of HPV-related (pre-)malignant lesions of the uterine cervix, vulva, and penis.

Innovative systemic therapies for penile cancer

PURPOSE OF REVIEW

The purpose of this review is to look at recent advancements and treatment options of systemic therapies to treat penile squamous cell carcinoma (PSCC). PSCC is a rare cancer that remains with limited funding for research and systemic therapy development. This review aims to discuss the most recent advancements in systemic treatments and our understanding of PSCC.

RECENT FINDINGS

Neoadjuvant chemotherapy (NAC) and adjuvant therapy remain integral parts of treatment in locally advanced PSCC. New potential drug regimens are being studied to expand on the availability of first-line regimen options. There has been a large development in discoveries of cellular pathways and immune system targets as potential treatment options but these therapies as of today have limited trial evidence and currently have no support to be used in a clinical setting.

SUMMARY

PSCC is a rare genitourinary cancer with limited treatment options for patients with advanced disease that is refractory to chemotherapy. Although many new therapies targeting the immune system and cellular pathways are being developed for other studies, clinical and translational research for PSCC are still understudied and underfunded.

Multimodal Treatment Combining Salvage Surgery-Assisted Chemotherapy and Checkpoints Blockade Immunotherapy Achieves Complete Remission on a Recurrent Penile Cancer Patient: A Case Report

Penile squamous cell carcinoma (pSCC) is a rare disease in developed countries. pSCC causes a severe health problem and social burden in developing countries. We reported a 49-year-old male recurrent pSCC patient with medium PD-L1 expression and low TMB. The patient obtained complete response after multimodal therapy (MMT). The clinical manifestation is a recurrence in the right groin with nearly ruptured pSCC. He had partial resection of penile cancer plus bilateral groin lymph node dissection and pelvic lymph node dissection during the first operation. Pathology of the recurrent tumor showed fibrous tissue with cancer infiltration and necrosis. We used MMT, including resection of palliative right inguinal metastases, four cycles of paclitaxel+bleomycin+cisplatin, and continuous sintilimab to treat the patient. The patient had a complete response (CR) after four cycles of therapy and sustained CR for 18 months with continuous sintilimab, showing a good tolerance and acceptable toxicity. This is the first case presenting a complete response in a relapsed pSCC patient. These results suggest that MMT is worth exploring.

Cemiplimab for Cisplatin Resistant Metastatic Penile Cancer

We report on a 75-year old man who presented with metastatic, squamous-cell carcinoma (SCC) of the penis whose disease had progressed after radiotherapy (RT) and cisplatin-based chemotherapy (CT). A strong PD-L1 expression as well as a CDKN2A mutation was documented, and he was given cemiplimab every 3 weeks at time of disease progression. Complete response (CR) was demonstrated after 10 cycles, and no toxicity was reported. However, this treatment was stopped after 13 cycles when the patient developed moderate severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pneumonitis which required a 2-week hospitalization for oxygen support. Six months later, he remains in CR. To our knowledge, this is the first demonstration of a CR with cemiplimab in a metastatic penile SCC patient previously treated with CT and RT for relapse. Furthermore, the patient remains disease-free despite cemiplimab was withdrawn due to SARS-CoV-2 pneumonitis.